Regioselective Synthesis of 5-Alkylsalicylates, 5-Alkyl-2-hydroxy-acetophenones, and 5-Alkyl-2-hydroxy-benzophenones by [3 + 3] Cyclization of 1,3-Bis(silyl enol ethers) with 2-Alkyl-1,1,3,3-tetraethoxypropanes

摘要

A variety of 5-alkylsalicylates, 5-alkyl-2-hydroxy-acetophe-nones, and 5-alkyl-2-hydroxy-benzophenones was regiose-lectively prepared by TiCl_4 mediated formal [3 + 3] cyclization of 1,3-bis(silyl enol ethers) with 2-alkyl-1,1,3,3-tetraethoxypropanes.